Study of Fast Electron Transport into Imploded High-Density Plasmas Using Cu-doped CD Shell Targets

Details of fast electron transport and energy coupling into the imploded high density plasma core are characterized using fluorescence from Cu added to the CD shell of a cone-guided Fast Ignition (FI) target. Like previous integrated FI experiments [1], this work uses the OMEGA 60 beams (18 kJ) for fuel assembly, and the high intensity EP beam (10 ps, 1.5 kJ, $I_{peak}>10^{19}\,$ W/cm$^2$), focused onto the inner cone tip, to produce fast electrons. Transport and energy coupling are diagnosed by measuring the induced Cu K-shell x-ray radiation (total yield and spatial distribution) from the imploded Cu-doped shell, complemented with neutron yield measurement. The escaped electron energy spectra are also recorded at several angles. Experimental results and comparison to Monte-Carlo and hybrid PIC calculations will be presented.\par \vskip6pt \noindent [1] W Theobald et~al., Phys.\ Plasmas {\bf 18}, 056305 (2011).